A cryptographic currency may be a peer-to-peer digital currency in which a user of the cryptographic currency may transfer a value from a public key-address under a control of the user to a different public key-address under a control of a different user through a transaction that is propagated across a cryptocurrency network. The user may have many unique instances of the public key-address, as the user may be able to generate a new public key-address at will with a key generation software. For example, the user may create the new public key-address for each transaction. To allow the peer-to-peer cryptographic currency to function without a central authority, the set of transactions may be recorded in a peer-verification ledger at a set of cryptographic nodes that comprise the cryptocurrency network. The peer-verification ledger may be a publically available data comprising an entire set of the previous transactions of the cryptographic currency to allow the cryptographic node to verify the transaction is valid (e.g., to verify that a value is currency associated with the public key-address that the transaction is purporting to transfer the value from). The peer-verification ledger, while including within the publically available data a set of transactions and an associated set of public key-addresses that the value has been transferred to and/or from, may not have any information regarding a true identity of who may control a particular public key-address (e.g., who may control the private key that may allow the value transfer from the corresponding public key-address). The cryptographic currency may therefore be “pseudonymous,” that is, anonymous until the user discloses his or her control of the public key-address.
The cryptographic currency may be used by both a legitimate user and an illegitimate user. The illegitimate user may use the cryptographic currency to purchase contraband, support crime, and/or participate in terrorist activity. An analyst, who may be a law enforcement agency and/or an intelligence agency, may therefore be interested in monitoring or thwarting activity of a user of interest who is transacting in the cryptographic currency.
However, due to the pseudonymous nature of the cryptographic currency, the analyst may be unable to tell who sent and/or received the value of the cryptographic currency within a particular transaction. Criminals and/or terrorists, who may be synonymous with or comprise the user of interest, may continue to transact anonymously. Additionally, a thief of the cryptographic currency itself may use a hacking technique to obtain the private key of a legitimate user of the cryptographic currency and steal the value associated with the corresponding public key-address. Further, the user of interest may transact in several instances of the cryptographic currency, further complicating detection and surveillance efforts. The user of interest may therefore operate financially outside the control of a government authority that might otherwise be able to reduce crime and/or prevent terrorism by analyzing a set of global financial transactions.